Growth and development of a woman's breasts is a process that begins before birth and culminates in pregnancy and lactation. Growth of tissues within the breast are tightly regulated by a number of factors within the body, including circulating hormones. Breast cancer develops when cells do not respond normally to regulation from the body and instead proliferate uncontrollably to form a tumor or tumors. A number of factors can increase an individual's risk of developing breast cancer.
Genetics
Genetic mutations passed down from parents can increase a person's risk of developing breast cancer. Mutations could help activate genes that cause breast cells to divide more quickly, or inactivate genes designed to protect against the development of cancer. Patients with a family history of breast cancer may have a genetic predisposition to developing breast cancer as well.
Mutations to two genes, called BRCA1 and BRCA2, are well known to predispose patients to breast and ovarian cancers. BRCA1/2 are genes responsible for preventing the development of cancer, and mutation of both genes leads to cancer. Women who inherit a mutated form of BRCA1 or BRCA2 are five times more likely to develop breast cancer, according to the National Cancer Institute. Genetic screening for mutations to BRCA1 and BRCA2 can be performed in patients with a history of breast cancer.
Diet
Lifestyle choices can play a role in the development of breast cancer, including diet. A healthy diet is high in fiber, lean protein, fruits and vegetables, and low in saturated fats, refined carbohydrates and alcohol. Components of a healthy diet may decrease the risk of breast cancer, while parts of an unhealthy diet can contribute to breast cancer.
In a 2004 study published in the journal "Breast Cancer Research," Dr. M. Holmes reports that vitamin A may help protect against cancer. Women with low levels of vitamin A in their blood developed breast cancer twice as often as those with adequate vitamin A levels.
The same study reports that ingesting large amounts of alcohol can contribute to the development of breast cancer. This may be because the metabolism of alcohol within the body increases estrogen levels, which can promote breast cancer growth. Women who consume alcohol are at a higher risk for developing cancer than those who abstain from alcohol, and the risk of cancer increases as more alcohol is consumed.
Hormone Replacement Therapy
Hormone replacement therapy in menopausal women can also increase the risk of developing breast cancer. This is because hormone replacement therapy involves ingesting estrogen and progesterone, two female hormones which stimulate normal breast cell growth and development. Estrogen and progesterone promote the growth of breast cancer cells.
The National Cancer Institute (NCI) reports that women taking hormone replacement therapy have a significantly higher risk of developing cancer. NCI recommends that women interested in hormone replacement therapy seek low doses and short periods of treatment to alleviate adverse symptoms of menopause.
